1. Field of the Invention
The present invention relates to a cassette for receiving glass substrates, and more particularly to a cassette for receiving glass substrates, capable of preventing the glass substrates from being damaged even if a distance between the glass substrates becomes small.
2. Description of the Prior Art
As is generally known in the art, cassettes for receiving substrates have been used in semiconductor manufacturing processes and flat panel display manufacturing processes. Among those cassettes, a cassette used in the flat panel display manufacturing process receives a plurality of glass substrates therein in order to load/unload the glass substrate on/from manufacturing equipment. That is, the cassette is used as a transferring device for the glass substrates received therein.
FIG. 1 is a perspective view showing a conventional cassette for receiving glass substrates. As shown in FIG. 1, the conventional cassette 10 includes a lower rectangular plate 12, an upper rectangular plate 14, and a plurality of support bars 16 vertically aligned between the lower and upper rectangular plates 12 and 14. The lower and upper rectangular plates 12 and 14 have a cross-shaped frame therein. The support bars 16 are positioned corresponding to edges and middle portions of both longitudinal sides of the lower and upper rectangular plates 12 and 14. Particularly, the support bars 16 include a plurality of gap maintenance rings 18, which are aligned lengthwise along the support bars 16 in order to ensure a sufficient distance between glass substrates 1.
Herein, each of the gap maintenance rings 18 has a thickness of about 2 mm, and the distance between the glass substrates 1 is about 1 cm.
A thin film transistor liquid crystal display device including an array substrate and a color filter substrate is fabricated through a lithography process. In particular, the array substrate must be fabricated through the lithography process. That is, when fabricating the array substrate, photoresist is firstly coated on an etch layer and a photoresist pattern is formed by performing exposure and development processes with respect to the photoresist. Then, the etch layer is etched to have a predetermined pattern by using the photoresist pattern. Then, the photoresist pattern is removed from the etch layer.
Herein, when a wet-etching process is carried out with respect to the etch layer or when the photoresist pattern is removed from the etch layer, a plurality of glass substrates (for example, 24 glass substrates) are received in a cassette and the cassette receiving the glass substrates is immersed in a bath having chemicals or cleaning solution therein for a predetermined period of time in such a manner that all glass substrates are simultaneously subject to the etching process or the photoresist pattern removing process.
However, when the size of manufacturing equipment is reduced, that is, when the size of the chemical bath is reduced, it is necessary to reduce the size of the cassette receiving the glass substrates. Herein, if the size of the cassette becomes reduced, the glass substrates must be aligned in the cassette while forming a narrower interval therebetween. In this case, as shown in FIG. 2, although the size of the cassette becomes reduced, a flow of chemicals 22 or cleaning solution may be disturbed by the glass substrates 1 when performing the wet etching process, so an optimum process condition cannot be achieved. In addition, as shown in FIG. 3, since the glass substrates 1 having thin thickness may be bent during the wet etching process, a glass substrate makes contact with an adjacent glass substrate, causing scratches or dry faults to the glass substrates 1. In addition, while the glass substrates 1 are being unloaded from manufacturing equipment after the manufacturing process has been finished, the glass substrates 1 may collide with an unloading robot 30, so that the glass substrates 1 may be broken.
Reference numeral 20 shown in FIG. 2 represents a chemical bath.